Correct patch attached.
>From 91ff271acffdb00bb8a7ace0ae1e811770104fc2 Mon Sep 17 00:00:00 2001
From: Lynne <[email protected]>
Date: Thu, 19 Oct 2023 04:36:12 +0200
Subject: [PATCH 2/2] aacdec: padding skip improvements
For some reason, this was never set, which meant all **raw** AAC in ADTS
streams, except faac, had extra samples at the start.
Despite this being a standard MDCT-based codec with a frame size of 1024,
hence a delay of 1024 samples at the start, all major encoders, excluding
faac and ffmpeg, use different amounts of padding.
---
libavcodec/aac.h | 1 +
libavcodec/aacdec_template.c | 20 +++++++++++++++-----
2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/libavcodec/aac.h b/libavcodec/aac.h
index 285d3b7482..79bbb3cce5 100644
--- a/libavcodec/aac.h
+++ b/libavcodec/aac.h
@@ -298,6 +298,7 @@ struct AACContext {
AVCodecContext *avctx;
AVFrame *frame;
+ int override_padding;
int is_saved; ///< Set if elements have stored overlap from previous frame.
DynamicRangeControl che_drc;
diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index 954399f86b..d5855a4f98 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -1273,6 +1273,9 @@ static av_cold int aac_decode_init(AVCodecContext *avctx)
if (ret < 0)
return ret;
+ /* Usually overridden by side data */
+ avctx->internal->skip_samples2 = ac->override_padding;
+
return 0;
}
@@ -2417,14 +2420,16 @@ static int decode_dynamic_range(DynamicRangeControl *che_drc,
return n;
}
-static int decode_fill(AACContext *ac, GetBitContext *gb, int len) {
- uint8_t buf[256];
+static int decode_fill(AACContext *ac, GetBitContext *gb, int len)
+{
+ uint8_t buf[256] = { 0 };
int i, major, minor;
if (len < 13+7*8)
goto unknown;
- get_bits(gb, 13); len -= 13;
+ get_bits(gb, 13);
+ len -= 13;
for(i=0; i+1<sizeof(buf) && len>=8; i++, len-=8)
buf[i] = get_bits(gb, 8);
@@ -2433,8 +2438,10 @@ static int decode_fill(AACContext *ac, GetBitContext *gb, int len) {
if (ac->avctx->debug & FF_DEBUG_PICT_INFO)
av_log(ac->avctx, AV_LOG_DEBUG, "FILL:%s\n", buf);
- if (sscanf(buf, "libfaac %d.%d", &major, &minor) == 2){
- ac->avctx->internal->skip_samples = 1024;
+ if (!ac->override_padding) {
+ if (sscanf(buf, "libfaac %d.%d", &major, &minor) == 2){
+ ac->avctx->internal->skip_samples = 1024;
+ }
}
unknown:
@@ -3471,6 +3478,9 @@ static const AVOption options[] = {
{ "coded", "order in which the channels are coded in the bitstream",
0, AV_OPT_TYPE_CONST, { .i64 = CHANNEL_ORDER_CODED }, .flags = AACDEC_FLAGS, "channel_order" },
+ { "padding", "Override the padding at the start of a stream.\n",
+ offsetof(AACContext, override_padding), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 8192, AACDEC_FLAGS },
+
{NULL},
};
--
2.42.0
_______________________________________________
ffmpeg-devel mailing list
[email protected]
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
[email protected] with subject "unsubscribe".
